1. Field of the Invention
The disclosure refers to a heart assistance device for the pulsatile delivery of blood.
2. Discussion of the Background Art
Mechanical circulatory support systems (VAD: ventricular assist devices) find clinical application for about 15 years and are the last option for the preservation of life in cases of manifested cardiac insufficiency. Heart assistance systems take over a part of the pumping work and thereby stabilize circulation until a donor organ is available. Recent studies have shown that, under this therapy, the heart function can improve as far as to allow an explantation of the system without subsequent heart transplantation.
Artificial heart pumps can be adapted to various requirements and are available without any waiting period. However, there are limitations with respect to the technology used and the compatibility. For example, the blood can be damaged by the pumping. The power supply to the systems, which are presently exclusively electrically operated, via wires through the abdominal wall, bears a high risk of infection for the patient.
Low degrees of efficiency lead to high energy consumption and to a heating up of the surrounding tissue. Assisted circulation often has to be kept up for months or years. Further, the systems are subjected to high mechanic stresses. Since a short-term replacement of the blood pumps is not possible, they have to feature a high durability and operational reliability.
With known drives for heart assistance devices the structural size makes implantability impossible to achieve in some cases. Further, a high wear of mechanical parts of the drive, and thus a shortening of the useful life, exist. Moreover, loud driving noises can occur. Other known disadvantages are a low degree of efficiency or a low output that translates as a low volume flow and an insufficient assistance. Known implantable pumps only have one pump chamber which can assist only one ventricle, preferably the left one. Further, implantable single chamber pumps additionally require a compensation for the volume delivered. Presently, this problem is solved with a volume compensation container (vent) that has to be implanted along with the device and causes additional complications.
It is an object of the present disclosure to provide an improved heart assistance device that in particular is simpler to implant.